Error message

At least once a day my pc loses connection to the internet where I have to reboot my PC to reconnect to the internet. I checked out event viewer and each time it happens I get the following error "name resolution for the name dns.msftncsi.com timed out after none of the configured DNS servers responded.

What is causing this and how do I fix it? OS is Win 7 home premium SP1 64 bit. I already replaced them modem once.